1.1. Concepts.

Flavour results from compounds that are divided into two classes: those responsible for taste and those responsible for odours. However, there are compounds which provide both sensations.

Compounds responsible for taste are generally non-volatiles at room temperature. Five basic taste perceptions can be referred: sour, sweet, bitter, salty and pungent or prickly compounds.

Compounds responsible for odours, often designated as aroma substances, are volatile compounds.

The concept of aroma substances, like the concept of taste substances, should be used loosely, since a compound might contribute to the typical odour or taste of one food, while in another food it might cause a faulty odour or taste, or both, resulting in an off-flavour.